"Shit. What a weapon."
But also the word is also being used to congratulate fellow buddies when somthing comendable is carried out.
Its completely down to the tone of voice used.
Drinker 2 : 'Sorry mate'
Drinker 1 : 'Weapon'
Take note the word weapon was used for a second time, this is a kick in the balls to whoever the word weapon is aimed at.
However on the flipside
Drinker 1 : 'Did you see Rooneys goal!!'
Drinker 2 : 'Hes a weapon'
Drinker 1 : 'Is that Patrice Evra, hes a weapon'
Soldier 1: Hey, Lieutenant!
Soldier 2: Yeah?
Soldier 1: Bring your weapon (smirks)
Soldier 2: I got it right here (grabs crotch.)